Conquest of the Aztec Empire

The Conquest of the Aztec Empire occurred from February 1520 to 12 August 1522, when the Spanish Empire and its indigenous allies successfully conquered the Aztec Empire of Mexico during the early days of the Spanish colonization of the Americas. Led by conquistador Hernan Cortes, a handful of Spanish soldiers and several thousand Tlaxcalan and other native allies entered the Aztec capital of Tenochtitlan, took the emperor Moctezuma II hostage, and departed to deal with rival Spanish forces sent from Cuba to arrest the mutinous Cortes. In the meantime, an Aztec revolt freed Tenochtitlan from Spanish rule, so Cortes formed new alliances with the natives with the help of his mistress and interpreter, Malinche, and the Spanish-Native army proceeded to storm Tenochtitlan, which had been severely weakened by a smallpox epidemic which killed 50% of the Aztec Empire's population. On 13 August 1521, the Spanish conquered Tenochtitlan, taking the new Aztec emperor Cuauhtemoc captive and ending the Aztec Empire.

Background
In April 1519, the Spanish conquistador Hernan Cortes landed at San Juan de Ulua, Mexico with 508 soldiers, 100 sailors, and 14 small cannon. Governor Diego Velazquez, the man who had dispatched Cortes to Mexico, attempted to recall him before he even left Havana, Cuba, as he wanted to replace his rival Cortes with another expedition leader; however, Cortes ignored his orders and founded the city of Veracruz on the Mexican mainland, becoming magistrate and, therefore, taking orders only from Emperor Charles V himself.

The local Native Americans believed that Cortes was the personification of their god Quetzalcoatl, a god whose return was predicted to come from the same direction and in the same year as Cortes' arrival. The Aztec emperor Moctezuma II sent emissaries bearing gifts to meet Cortes at Quauhtechcac, as Moctezuma feared that the Spanish would wrest control of his empire from him. Cortes and his force nevertheless continued to march on the Aztec capital of Tenochtitlan, which they entered on 8 November 1519. Cortes was amicably received by Moctezuma, but he was taken hostage by the Spanish six days later as a safety measure. Moctezuma's captivity led to the Aztecs being forced to send food and supplies to the Spanish, sustaining their presence in the Aztec capital.

Siege
Cortes was distracted by news of the arrival of 800 Spanish soldiers under Panfilo de Narvaez at San Juan de Ulua, as Velazquez had sent Narvaez to capture Cortes and bring him back to Cuba. Cortes left Tenochtitlan with his army, leaving Pedro de Alvarado and just 80 Spanish soldiers in charge of defending the city. Alvarado interfered with native customs when he demanded that no human sacrifice occur during the Toxcatl festival in May, and he tortured several priests and nobles when he heard that the Aztecs were planning to continue with the human sacrifice. He also discovered news of an upcoming revolt, and the paranoid Alvarado sent his men to the Great Temple when he heard flutes and drums playing; he mistook the festival's music for signals for a revolt. His men massacred thousands of Aztec nobles, warriors, and priests, resolutely turning all the Aztecs against the Spanish and undermining Moctezuma's authority.

Upon hearing news of the planned revolt, Cortes - who had defeated Narvaez and incorporated his soldiers into his own army - hurried back to Tenochtitlan on 24 June with 1,300 soldiers, 96 horses, 80 crossbowmen, 80 arquebusiers, and 2,000 Tlaxcalan warriors. After Cortes' forces entered the city, the roads were shut and the causeway bridges were raised, and the Aztecs killed or wounded every Spanish soldiers in the palace. Cortes failed to parley with the Aztecs, so he sent out Moctezuma; he was stoned to death by his own people while attempting to convince them to surrender. Cuitlahuac was chosen as the new Aztec emperor, and the Aztecs went on the warpath. As Cortes' army attempted to withdraw from the city, its rearguard was massacred in the Night of Sorrows, and both Cortes and his lieutenant Pedro de Alvarado were wounded.

However, the Aztecs made the mistake of underestimating their smaller Spanish foe. At the 7 July 1520 Battle of Otumba outside the capital city, the Spanish charged and killed the Aztec commander and most of their other leaders (whom they identified from their bright plumage), and the Spaniards' Tlaxcalan allies - wielding Spanish swords and shields - also played an important role in the battle. Cortes reached Tlaxcala five days after leaving Tenochtitlan, having lost over 860 Spanish soldiers, over 1,000 Tlaxcalans, and Spanish women who had accompanied Narvaez's troops.

Cortez took his time with rebuilding his forces, using diplomacy against the Aztecs. The Aztecs, who had plenty of enemies, were considered to be more of a threat to their neighboring city-states than the Spanish, and Cortes formed alliances with several smaller native tribes, including former Aztec member states such as Texcoco. At the same time, an outbreak of smallpox in October 1520 wiped out 50% of the Aztec population, and Cuitlahuac died sixty days into his reign.

Fall of Tenochtitlan
The smallpox-stricken city of Tenochtitlan had been severely weakened, but the Aztec emperor Cuauhtemoc insisted on continuing the fight against the Spanish. Cortes' 1,400 Spanish troops were reinforced by 200,000 native allies, and they faced 300,000 Aztec warriors within the city's walls. On 22 May 1521, the siege began. Spanish forces under Pedro de Alvarado and Cristobal de Olid marched towards Chapultepec to disconnect the Aztecs from their water supply, and the Aztecs forced them back at Tlacopan. However, the Spanish brigantines destroyed the Aztec canoes at the Tepeaquilla causeway, and the Spanish took control of the causeways, preventing food and water from being delivered to the city. Cortes discovered Aztec plans to ambush his army, so he launched counter-ambushes, devastating the Aztecs and preventing the Aztecs from ambushing his army again, or openly bringing food and water into the city. Cuauhtemoc and his entire army then attacked all three Spanish camps simultaneously, capturing five of Alvarado's men, who were then sacrificed at the Great Temple in full view of their comrades. The Aztecs continued to attack the Spaniards on the causeways day and night, and many of Spain's native allies lost their lives, went home wounded, or simply deserted. Both sides fought desperately, but Cortes let the Aztec eat up all of their provisions and drink their brackish water. The Spanish gradually advanced down the causeways, albeit without allies, and many Spanish allies would return after the Aztec prophecy that all Spaniards would be dead within ten days turned out to be false. The Spanish, who constantly received supplies from Veracruz, outlasted the starving Aztecs, whose changes of tactics merely delayed the inevitable fall of their city. Cortez then had all three camps of his men advance on the Tlatelolco marketplace, where fierce fighting ensued; the Aztecs ate the hearts of 90 Spanish captives. However, the Tlaxcalans, who, for a hundred years, had been forced by the Aztecs to send a quota of young men and women to them for sacrifice, took out their vengeance on the Aztecs, with the 150,000 Tlaxcalans massacring over 15,000 Aztec civilians. After discussions with his nobles, Cuauhtemoc finally decided to begin talks with the Spanish. After several failed peace overtures, Cortes had Gonzalo de Sandoval attack the part of the city to which Cuauhtemoc had retreated, and, as hundreds of canoes attempted to flee the doomed city, Cortes sent his brigantines to intercept them. Cuauhtemoc's fifty pirogues, laden with his property, gold, jewels, and his family, were captured, and Cuauhtemoc himself was brought before Cortes. On 13 August 1521, the Aztecs surrendered, and Cuauhtemoc remained the titular leader of Tenochtitlan until 1525, when he was hanged for treason during a Spanish expedition to Guatemala. Almost all of the Aztec nobles had been killed during the siege, while 40,000 Aztec bodies floated in the canals or were awaiting burial after the siege's end. Most of the survivors were young women and very young children, as most of the men had been slain in battle. The Tlaxcalans went on to loot the city, massacring women and children; 6,000 were massacred in Ixtapalapa alone. The Aztecs were almost wiped out as a result of the fall of Tenochtitlan and the smallpox epidemic, and the Spanish were able to conquer much of Mexico, gain substantial access to the Pacific Ocean, and achieve their original goal of reaching Asian markets.